In general, as a heat exchanger, a heat exchanger provided with a plurality of heat transfer tubes provided inside a body, and a plurality of heat transfer tube support apparatuses supporting the heat transfer tubes has been proposed (refer to Patent Document 1). In this heat exchanger, heat exchange is performed between an in-tube fluid flowing inside the heat transfer tubes, and an out-of-tube fluid flowing outside the heat transfer tubes in the opposite direction to the in-tube fluid.
In addition, an egg-crate turbulence promotion mechanism is provided in this heat exchanger in the heat transfer tube support apparatuses. Thus, since the laminar flow of the fluid is disturbed when the fluid flowing outside the heat transfer tubes flows in a portion between the heat transfer tubes and the egg-crate turbulence promotion mechanism, heat exchange is efficiently performed between the fluid flowing outside the heat transfer tubes and the fluid flowing inside the heat transfer tubes.